CBR or VBR with 2 pass?

Shane Jensen wrote on 2/9/2006, 3:02 PM
I have less than an hour of video captured from a standard Video8 8mm video tape. One part of the video was shot with a Sharp Viewcam and the other part was shot with a Sony Handycam (both Video8 8mm). The footage was captured using the ADVC-300 analog to digital conversion box connected to the computer via firewire. The raw AVI footage looks fantastic, better than the original tape with the ADVC-300's filters set.

Anyway, I rendered out my footage as MPEG2 at 8,000 Kbps CBR for DVD. They still look fantastic, however, I'm still a little unsatisfied with the quality. I can totally see that the quality isn't as good as the raw AVI, but that's to be expected with how much compression is at work here. However, I do have 8,000 Kbps compression ratio here so we're not talking a low compression.

What I was wondering is could I get a better picture if I choose VBR at 8,000 Kbps using 2 pass? Should I set the three fields as 7,800 Kbps, 7,900 Kbps, & 8,000 Kbps? Or just keep all three fields at 8,000 Kbps? I'm mainly interested in the 2 pass. Would that help me with a better picture either way?

Comments

farss wrote on 2/9/2006, 3:15 PM
CBR at 8mb/sec is as good as it gets, you might just get away with a slightly higher bit rate if using ac3 audio but I seriously doubt it's going to help much. Two things to check though.

1) Is your vision within legal limits.

2) How much noise is in the video, noise can eat up bandwidth big time. Many, many ways to reduce noise and many good posts on this topic.
Shane Jensen wrote on 2/9/2006, 3:29 PM
My vision? You mean my eye vision? My eye vision is as good as it gets.

How much noise? Just standard from an analog video camera.

Here's a sample, it's 15 MB. http://www.megaupload.com/?d=7AN27M8F
Serena wrote on 2/9/2006, 3:58 PM
Glad you've 20/20 eyesight. Now, is your video within broadcast limits? How about putting up a shorter sample - 15MB is more than I wish to download.
Shane Jensen wrote on 2/9/2006, 4:09 PM
I think it's within brodcast limits. I just use the DVD NTSC template in vegas when I render. What else should I do to make sure it's within brodcast limits?
Shane Jensen wrote on 2/9/2006, 4:13 PM
Here's a sample from my old Sharp Viewcam. It's 5.25 MB. http://www.megaupload.com/?d=K67JIO4H
farss wrote on 2/9/2006, 4:24 PM
That clip is very noisy and I'd mask out the line tearing at the bottom.
Mike Crash's temporal NR filter has worked fine for me in the past on that kind of footage. There are other ways that are reported to be better but a bit more complex and time consumming.
To check that your vision levels are within legal limits look on your video scopes and read Genn Chan's excellent tutorials on the VASST site. But I think your biggest problem is the noise.
Bob.
craftech wrote on 2/9/2006, 4:36 PM
8000 CBR should give better results than that. Are you sure DVDA isn't recompressing the video when you author it? If not, then it may be the analog quality you started with. If you have a Proc Amp, recapture after first going through the Proc Amp and setting it to legal limits and color correcting it as well. Alternately you may want to try John Meyer's Ultimate VHS Tape Resoration Recipe.

John
Shane Jensen wrote on 2/9/2006, 7:39 PM
Craftech, I have not yet authored this video with DVDA and No, I never have it set to recompress the video. Like I said in my original post, the captured footage is actually better looking than that of the original tape because of the filters in my capture box. So, it's probably because of the analog quality I started with because when I do the same editing and compression with my MiniDV tapes it looks way better than that.

I have no idea what a Proc Amp is. I can't spend any more money right now, I just have to make due with the equipment I have which isn't too bad. I use a Sony HI8 video camera to play back my Video8 8mm tapes using the S-Video out. That inputs to my ADVC-300 video capture box which has a few filters. I'm very conservative with the filters as to not over modulate anything which I have done a few times in testing back when I first got the box.

As for the other methods you linked, they are just way too time consuming. Really makes me want to just throw my hands up and not bother archiving my old analog videos to DVD anymore and stick with the VCRs for playback whenever I want to watch. :(
Shane Jensen wrote on 2/9/2006, 7:53 PM
Farss, how do I mask out the line tearing at the bottom? Also, where do I get this NR filter?
johnmeyer wrote on 2/9/2006, 8:16 PM
I haven't looked at the clip, but what template did you use when you rendered? I'm not asking about bitrate, but what template? The "default" template will produce AWFUL video. You MUST use the appropriate "DVD Architect" template.

2-pass is a total waste of time for high bitrates. It will give you zero improvement at the rates at which you are encoding and, of course, will take twice the time.

Mike Crash's filters can be found here:

Mike Crash Vegas Filters

You want the Dynamic Noise Reduction. Once you install it and apply it to an event, DO NOT overdo it. Play around with until you get a setting you like, and then use about 2/3 of that amount. Everyone always uses too high settings, and then later starts to discover all the artifacts they've created.

If you use my VHS recipe given in the earlier link, ignore all the nonsense about multiple captures. It's an elegant solution that works wonderfully, but it will take you several days to capture two hours of stuff. If you're restoring something for the National Archives, then go for it.

I've gotten way better at de-noising video and have all sorts of VirtualDub and AVISynth filters to recommend. The people over at doom9.org have invented an amazing array of filters and techniques, depending on what problems your video might have. Some of it gets pretty exotic and involves first de-interlacing, then motion compensating, then filtering, and then putting the video back together in an interlaced form. This is far more than you want to do. However, if the Mike Crash filter is not enough, then read some of these posts:


Dust and Scratch Filters for VHS

Vegas Video Denoise for VHS

VirtualDub Filter Chain for VHS

My VHS Tape Restoration "Recipe"


farss wrote on 2/9/2006, 8:24 PM
A number of ways, you can use the Border FX in Vegas to clean up all the edges apart from the bit at the bottom. For that add a track of Generated Media / Solid Black and use Event or Track Pan/Crop to move it so it just covers the bottom portion.

To save render time the ADVC-300 has adjustable 3D and 2D noise reduction. You can load the Canopus control applette to control these and more paramaters during capture, works fine with VidCap. You can hook a monitor to the outputs of the 300 to see what you're doing during capture. The Canopus 3D noise reduction is temporal noise reduction and if used heavily does cause some ghosting however it is a very quick method. All those tweaks in the ADVC-300 are part of a Proc Amp, no need to buy anything more hardware wise.

Hope all this helps.

Bob.
Shane Jensen wrote on 2/9/2006, 8:30 PM
Johnmeyer, I never user the default template. I always use the DVD NTSC template. You say I should use one of the DVD Architect templates? The only ones in my dropdown menu are DVD Architect video streams. The one that would be for me would be the DVD Architect NTSC Video Stream. Those are video only, however, I never use the audio from the rendered MPEG2 because DVDA always recompresses the audio. I always render out the audio to a WAV and use that in DVDA.

That's for those links and tips. I don't think I will be doing that recapturing twice stuff. Would take too much time.
Shane Jensen wrote on 2/9/2006, 8:33 PM
Farss, I have noticed ghosting with the 3D filters when used heavily. That is why I have all of my filters set to "Weak" as to not overmodulate.
farss wrote on 2/9/2006, 8:56 PM
Well, you're not "overmodulating" anything but yes they're probably not the worlds greatest DNR filters, mid seems about as far as you would want to go and Mike's noise filter does seem better.

In the end I think it all comes down to a bit of a balancing act between convenience, render times and final quality. I've spent ages fixing problems from VHS and the result was pretty amazing but I was very lucky that most of the frame was static and the client was paying as it was a historic corporate video.

Bob.
Steve Mann wrote on 2/9/2006, 10:22 PM
"Those are video only, however, I never use the audio from the rendered MPEG2 because DVDA always recompresses the audio."

Render once using the DVDA template and again using the AC3 template. DVDA will not recompress anything unless the file is too big for a DVD.
johnmeyer wrote on 2/9/2006, 11:37 PM
If DVDA recompresses anything, then you're doing something wrong.
Grazie wrote on 2/10/2006, 12:29 AM
. . when I download the "sample" it tells me it is not a movie file and passes along. Humphfff! ! !


G
farss wrote on 2/10/2006, 1:57 AM
It's mpeg-2, need a PC with a DVD player app on it or I think VLC will play it.
Grazie wrote on 2/10/2006, 2:19 AM
"It's mpeg-2, need a PC with a DVD player app on it . . "

I have.

" . or I think VLC will play it. " VLC?

G
Grazie wrote on 2/10/2006, 2:28 AM
Thanks Bob! PC not defaulting to DVD player s/w! STUPID machine! ! !

G
rs170a wrote on 2/10/2006, 3:00 AM
Grazie, VLC. A very (& free) nice app.

Mike
craftech wrote on 2/10/2006, 4:39 AM
Grazie, VLC. A very (& free) nice app.

Mike
================

Clicked on the link and got the following:

"The page you are looking for might have been removed, had its name changed, or is temporarily unavailable."

Grazie wrote on 2/10/2006, 7:00 AM
Mike? As per Craftie - link aint working?

G
craftech wrote on 2/10/2006, 8:07 AM
Mike Crash's filters can be found here:

Mike Crash Vegas Filters

You want the Dynamic Noise Reduction.

==========
I have never been able to download from that site. The 54KB file either times out or takes 10 minutes to download and is ALWAYS corrupt.

John